


Inside A Genius’s Brain

by afteriwake



Category: Sherlock (TV)
Genre: Background Case, Gen, Greg Lestrade & Sherlock Holmes Friendship, Greg Lestrade in Sherlock's Mind Palace, Inspired by Dreams, Lestrade Learns About Sherlock, Lestrade-centric, Mind Meld, Musing Greg Lestrade, Other Additional Tags to Be Added, POV Lestrade, Pre-Reichenbach, Season/Series 02, Sherlock's Mind, Sherlock's Mind Palace, Sherlock's Thinking Patterns
Language: English
Status: In-Progress
Published: 2018-05-15
Updated: 2019-02-27
Packaged: 2019-05-07 06:07:28
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 2,356
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14664879
Author URL: https://archiveofourown.org/users/afteriwake/pseuds/afteriwake
Summary: After musing that he would like to figure out just what makes Sherlock tick, he finds he has somehow been able to do just that...and he learns so much more about his consultant than he had ever thought possible.





	1. Chapter 1

**Author's Note:**

  * For [Chitarra](https://archiveofourown.org/users/Chitarra/gifts).



> So this fic was requested by **Chitarra** based on a dream she'd had that she thought would fit the Lestrade  & Sherlock friendship well, where Lestrade was actually in Sherlock's head, seeing how he worked. This will be multiple parts and _hopefully_ will not languish forever.

“You know, there are times I wish I could just...poke around in his brain,” Lestrade said quietly so Sherlock wouldn’t hear, not really to anyone in particular, but he knew Sally would comment.

“Why?” was her simple reaction, causing him to look at her.

“I suppose I just want to know how it works,” he said. “How he pulls these deductions out of a rabbit hat, I guess.”

Sally chuckled, the sound a little derisive. “I’d like to get inside and poke around and find out what’s messed up about it that makes him the way he is.”

Lestrade frowned. That wasn’t what he had meant, not really, but he knew Sally didn’t see Sherlock the same way he did. She viewed Sherlock as nothing more than a nuisance, really. A brilliant nuisance, but he made her job and her days harder. Sherlock didn’t really help in that regard, no matter how much he tried to smooth things out between them. And he would admit, there were some...peculiarities...to Sherlock, though over the years he’d seen them fade into something more akin to quirks.

But he just wanted to get even a fraction of a glimpse into the way his mind worked. Mycroft had once said Sherlock had a beautiful, complex brain that should have been hindered by his past drug use but seemed to brush it aside as though it was merely an irritating chemical reaction, and Lestrade could see that. He had known Sherlock for a long while, since his brother had sought out his help to save the man from himself.

Sometimes he even liked to think he had helped in the matter, but he wasn’t entirely sure. Sherlock, being Sherlock, was blunt and rude, even with those he cared for, and he always wondered which side of the divide he fell on.

He was shaken out of his thoughts as Sherlock approached them, pulling off his late gloves with a snap, the only consolation he made to being on a crime scene and not contaminating the place. Not that he would do it intentionally, but Lestrade had learned long ago that asking for Sherlock’s help meant playing by Sherlock’s ground rules, even if they only made sense to Sherlock. But they got results, and to his superior’s that meant Sherlock’s quirks were to be tolerated.

Within reason.

The day Sherlock crossed the line his arse would be banned from being allowed within a quarter-mile of any crime scene NSY operated. They were all very aware that rules could only be bent so far, restrictions could only be circumvented so long, and this was a game that they all had to acknowledge could blow up in their faces at any moment if Sherlock ever changed.

But it was a game Sherlock played well, so for now, all was well.

“It was suicide,” he said, tossing the gloves at John. “An elaborate one made to look like a murder, but the gunshot wound was no doubt self-inflicted. Molly Hooper will confirm that. You can trust her to notice the minute details most would miss.”

“But not you,” Sally said.

“No,” he replied, seemingly uninterested in a game of snark with Sally. “In my opinion, he rigged the gun that fired the shot by remote so it would look like it had been fired from a distance, but I doubt it’s far away from here. That is unless he has an accomplice.”

“An accomplice?” Lestrade asked with a frown.

“He’s a shady businessman. If you don’t find the gun, look into other people he was trying to take advantage of that he would have a personal distaste for, and then see who else shared his feelings on the matter. He would only trust one person, perhaps two, with his plan, but only someone who hated Lord Drummond as much as the victim did would frame him for murder. Be wary of any evidence you find implicating Lord Drummond, by the way. Chances are it’s planted.”

“And if it’s not?” Sally asked, crossing his arms.

“Then I’ll parade around Scotland Yard in just my pants,” he said with a sneer towards hers. “Doubt the evidence, for once. It’s a ruse.” He motioned to John to move away from them and they walked around, ducking under the crime scene tape moments later.

Sally shook her head. “What a prick,” she said under her breath before uncrossing her arms and moving in the opposite direction from Holmes, walking towards the victim. Lestrade watched her for a moment and then turned back to see Sherlock and John ducking into a cab.

He would give _anything_ to figure out how Sherlock ticked, he thought to himself. Anything at all...


	2. Chapter 2

Something felt a bit...different...when he woke up the next morning. The first thing that surprised him was the disconnect he felt, as though there was something different with his body but he couldn’t quite place his finger on it. He wondered if, perhaps, he’d fallen out of bed and concussed himself and then gotten back into bed without realizing it, but there was much to be done. He got ready, taking a shower and shaving while music played on the radio and he sang along to the good bits. He picked out a suit and shirt and almost thought of a tie for the press conference but changed his mind. Never wore one before, why would he wear one now?

And then he realized, he wasn’t living through his own life. He was…

“Hello,” he heard a voice say. “You noticed. Good.”

“I look like me,” Lestrade said, and then switched to a mental voice to match the familiar one he heard in his head. “I look like me, I’m in my flat...”

“But you’re living my life. You’re going to go about your day and everyone will assume you’re Geoff Lestrade but you’ll be living _my_ life while I teach you a few...life lessons, I suppose.” Sherlock didn’t sound annoyed, as he had thought he would in a situation where they were sharing a brain? Body swapped? He had no bloody idea and already it was giving him a headache. “Oh, come now,” Sherlock continued. “You’ve always wondered how I tick. Consider this your chance to have a hands-on experience. You’re going to live a life in the day of Sherlock Holmes as soon as you step out the door.”

“Then what’s to stop me from staying in the flat all day?” he asked.

“Life. Your curiosity. You know... _things_.” 

He went back to his bed and sat down, crossing his arms to think. Truthfully he didn’t want to live a day in the life of Sherlock Holmes, but then he _did_. Part of the reason he was a copper was the innate curiosity he could never seem to sate. Maybe not in the way that Sherlock seemed to have it, but bloody hell, there was an opportunity to learn exactly what made Sherlock tick and why would he pass it up? Slowly he got up off the bed, finished getting his clothing sorted, went for his coat and stepped out into London.

“Good job, Geoffrey,” Sherlock said. “Baby steps. We’ll make it to the leaps and bounds soon enough.”

“You promise we’ll take it slow?”

“For once, I’ll make a promise and keep my word. Baby steps and maybe someday, you’ll think similar to how I do.” The ghost in his brain let out a chuckle, which surprised him and then lapsed into silence. For a moment, he was on his own to explore what it was like in a genius’s brain.


	3. Chapter 3

He had assumed when Sherlock said he would live his life that Sherlock had meant _his_ life, but almost as soon as he’d made the decision to leave his flat his mobile rang with Sally on the line. “This one’s messy,” she said. “I don’t know if we want it.”

“Of course you do,” Sherlock said. “The messy ones are the most interesting.”

“Define interesting,” he said.

“Pardon?” Sally said on her end.

“I meant messy,” he said, mentally berating himself for not thinking at Sherlock as he had before. “Define messy.”

“Gun violence, for one, but there seems something odd about it, like the guns weren’t...right.”

“Oooh, this will be a good chance to show what I can do through you,” he said. “Tell Donovan we’ll take her messy case.”

“Give me a location and I’ll be there as soon as possible.” Lestrade paused. “Is this one of the lose your breakfast type cases?”

“We’ve seen worse. A lot of brain matter sticking to the bodies.”

“And that’s a clue there, that it’s on the bodies and not the walls,” Sherlock crowed. “Oh, she’s dropping gems like Hansel and Gretel dropped breadcrumbs.”

Honestly, Greg didn’t like this back and forth and it was already giving him a headache. “You, hush,” he said to Sherlock. Then he turned his attention back to his mobile. “Fine. Location?” She rattled off an address and he realized it wasn’t far from the NSY offices. He could get a quick bite and then get to the scene around the time he would normally clock into his office.

“No time to eat, don’t eat on a case. Best to keep your stomach empty to keep your mind ready to absorb everything in one fell swoop,” Sherlock said.

Lestrade grit his teeth. “I’ll skip breakfast and get there quickly. Twenty minutes or so, depending on traffic.” He hung up and then said out loud, “Happy? No food for me.”

“The body is quite similar to a machine. You’ll get food soon enough, I promise. But hunger puts things in sharp contrast. You notice all the details.”

“Wonderful,” he murmured. He slipped on his coat and grabbed the keys to the vehicle he was using from Scotland Yard and then got in.

“Sirens?” Sherlock asked, his voice almost boyish with hope.

“No need,” Greg thought.

There was a long enough pause that he assumed this inner Sherlock was pouting when Sherlock said quietly, “Please?”

That alone caused him to smile. “I suppose I could, just this once,” he said with a soft chuckle. He flipped on the sirens as he pulled out of his assigned spot in the car park and then made his way to the scene, turning the sirens off just before he arrived. Sally was out there, a frown on her face.

“Did you use your sirens?”

“Prats at a light,” he said. "Have to use the perks sometimes. And it’s not like it was a personal matter. We have a messy case.” He rubbed his hands together, and action he usually didn’t do. “Show the way?”

Sally gave him a look but she lifted up the tape and they went to put the crime scene suits on. She gave him the rundown and surprisingly, Sherlock stayed quiet in his head. There were a group of five men and an abandoned poker game. No sign of a gun but no sign of money, either, and from what they had been told, this was a high stakes poker game with plenty of cash on hand. The people coming in to look at the body before deciding where it was to be sent were baffled. Greg listened and nodded, taking it in.

Finally, Sherlock spoke. “Send it to Barts. If it is what I think it is, Molly’s seen it before and can confirm.”

“Oh?” Greg thought.

“Wax bullets. Worse than blanks but they don’t do quite the same amount of damage. But she’ll know if the damage is from a wax bullet or a blank, which is the other potential cause.”

“Can people really die from blanks?” he asked, forgetting to think the question.

“Brandon Lee did,” Sally said. “On the set of ‘The Crow’? There was a malfunction and the prop gun killed him. Supposedly the scene where he died is actually in the movie.”

“That’s rather morbid, even for my taste,” Sherlock thought. “But it’s true. Though it depends on if there’s damage where the muzzle would have been pressed to the head. Prop guns are easier to obtain than unlicensed handguns.”

“Have the body sent to Barts and make sure Molly sees it,” Greg said.

“Alright,” Sally said, heading over to the bodies with Greg. Greg knelt down to examine one of the bodies and its head wound.

“Yes. Definitely a wax bullet or a blank. Hard to tell without a pocket magnifier to tell the specific damage. You should carry one.”

“When I can just call you?” Greg thought.

“But one day I might not be there,” he said. “One never knows. There’s the continued game with Moriarty. We don’t know where that will lead.”

Greg conceded the point to himself. This game, whatever it really was all about, had put everyone on edge with the bomb scare. There was no telling what else the sociopath would do, or who else he would target. And with that maudlin thought, he stood up. “Let’s get uniforms to start canvassing for witnesses while we work on identifying each of the victims and looking into their backgrounds,” he said to Sally. She nodded and went to tell the people handling the bodies to take them to Barts. “I will owe Molly for this. Five bodies with everything else on her plate?”

“She’s fond of you. And you don’t manipulate her like I do,” Sherlock said.

“So I should start doing that?” Greg thought.

“No.” The way Sherlock said it sounded as though he might murder him on the spot if he attempted to do any such thing, and seemed to place another puzzle piece in place about the type of relationship he had with the specialist registrar.

“I won’t then. But I’ll still owe her.”

“Chocolate, coffee, and lunch,” Sherlock said. “That should do the trick. Have Sally give her bubble bath and Epsom salt for tonight. Her stores of both are low.”

“And just how would you know that?” Greg asked, murmuring the question out loud. But Sherlock stayed resolutely silent at that.

Figured.


End file.
